Improvement in grate-bars



UNITED STATES PATENT OEErcE.

CHARLES F. OURWEN, OF SALEM, MASSACHUSETTS.

IMPROVEMENT IN GRATE-BARS.

Specification forming part of Letters Patent No. 217,449, dated July 15, 1879; application filed June 6, 1879.

, To all whom it may concern:

V is shown in a grate-bar having two side ribs connected by short cross-bridges, preferably ruiming obliquely to the side ribs, said bridg'es being extended downward at the middle to join a strong longitudinal web, the said web coming in contact only with the lower or extended portion of the said bridges, the upper surface of the web being thereby loca-ted so far below the coal or other fuel upon the top of the bridges as not to serve as a support for the said fuel, as would be the case if the web extended, as usual, between and to the level of the top of the bridges. 'Leaving the space between the bridges open, and supporting said bridges only at their lower ends, as herein described, permits a free circulation of air between the bridges and entirely about the web at all sides, so that the latter always retains its original shape, and prevents the grate-bar warping or twisting', thereby increasing its durability and efficiency without adding to its cost.

Figure 1 is a top view, Fig. 2 a side view, and Fig. 3 a cross-section on line x Fig. 1,. of one of my improved grate-bars.

The side. ribs, a a, preferably channeled at their upper surface, as shown at b, and provided with lateral projections c, to abut against -correspondin g projections of the'neXt bar, and, with shorter intermediate projections d, are

joined at the ends of the bar by the flat portions e, and at short intervals along the bar by-the bridges. g, (here shown as running diagonally across and channeled at the top.) These bridges project downward near their middle portions, as shown at m, and unite with the strong longitudinal web n, the main body of which is below the rest of the grate-bar, and the top of which is below the .upper surface of the bridges gl This disposition of the parts permits the cool air of the draft to circulate around the web n, as shown by the arrows, so that it is but slightly attected by the heat.

l The web n itself and the connections thereof with the bridges g are sufliciently strong to prevent the upper portion of the bar next the re and aifected thereby from warping.

I claimp 1. A grate-bar consisting, essentially, ot' two lateral ribs and bridges connecting the same, and a central longitudinal strengthening-web mainlybelow the under surface of the rest of the bar, with space for the circulation of the air around and above it, substantially as and for the purpose set forth.

2. In a gratebar, the side ribs and bridges between them, the latter being connected with a longitudinal web,the upper surface of which terminates below the upper surface of the bridges to permit free circulation of air about the web, substantially as described. y

In testimony whereof I have signed Vmy name to this specification in the presence of two subscribing witnesses.

CHAS. F. UURVVEN.

Witnesses:

G. W. GREGORY, Jos. P. LIVERMORE. 

